Compressor for refrigeration system



July 22, 1958 A. B. NEWTON 2,844,301

COMPRESSOR FOR REFRIGERATION SYSTEM Filed Dec. 2;. 1954 l IN V EN TORIATTORNEYS.

COMPRESSOR FOR REFRIGERATION SYSTEM Alwiu B. Newton, Wichita, Kans.,assignor to The Colerltan Company, Inc., Wichita, Kans., a corporationof ansas Application December 23, 1954, Serial No. 477,364

13 Claims. (Cl. 230-53) This invention relates to a refrigerationsystem, and more particularly to compressor apparatus adapted for usetherein.

An object of this invention is to provide a refrigeration system havingnovel compressor apparatus therefor. Another object of the invention isto provide a compressor for compressing fluids and that is actuated byheat. Still another object is the provision of apparatus wherein thealternate condensing and evaporation of a suitable fluid is operative topower the apparatus whereby it is adapted to function as a compressorfor gaseous fluids. Yet another object is in providingcompressorapparatus having a piston and cylinder, the piston beingreciprocatedwithin the cylinder by the change of state of fluids therein; the pistonbeing operative during. its reciprocatory cycle to compress fluids suchas, for example, a refrigerant.

A further object of this invention is to provide com-- pressor apparatushaving a plurality of cylinders equipped with pistons mounted forreciprocation therein, the lower end portion ofeach of the cylindersbeing arranged to receive an expansible fluid therein; means beingfurnished to alternately heat and cool the lower cylinder ends, with theresult that the expansion and contraction of the fluid causes thepistons to reciprocate within the cylinders and to thereby compress afluid in the upper ends of the cylinders. Still a further object is toprovide a plurality of spaced-apart piston-equipped cylinders asdescribed above and to provide a heater adapted to be broughtsuccessively into heat-exchange relation with each of the cylinders; jetcoolant means also being provided for successively impinging a jet ofcoolant upon the cylinders subsequent to the heating thereof.

Still a further objectis in the provision of apparatus as describedwherein the means for providing the jet coolant is angularly orientedand the impingement of the coolant upon the cylinders is operative tomovethe jet and the heater operatively arranged therewith. Yet a furtherobject is in providing governor means for automatically controlling therate of movement of the heater and jet. A further object is to provide arefrigeration system wherein the refrigerant after expansion is.compressed by a heat-actuated pump, the pump comprising a pistonmounted for reciprocation within a cylinder, a suitable fluid beingprovided at one end'of the cylinder, and means also being provided toalternately heat the cylinder to evaporate the fluid and cool thecylinder to condense the fluid whereby the piston is reciprocated withinthe cylinder.. Additional objects and advantages will appear asthespecification.proceeds.

An embodiment of. the invention is illustrated. in the Referring nowspecifically tothe drawing, it is" seen Patented July 22, 1958 that arefrigeration system is illustrated that incorporates a compressorembodying my invention; The compressor vii includes a casing- 10 that issubstantially hollow throughout the interior thereof but which hasaligned centrally therein a hub or mounting member 11 rigidly secured atits upper end to an annular top wall or closure mem ber 12 which in turnis rigidly secured to the vertical Walls of the casing 10. The hub 11has side walls and a bottom wall and is open at the top thereof. the hub11 is annular and it may be secured to the closuremember 12 by anysuitable means such as welding or, if desired, cap screws, etc'., may beemployed to provide a releasable mounting for the closure member 12 uponthe hub. Similarly, the member 12 about its outer edge thereof may bepermanently secured to the vertical walls of the casing as by weldingbut preferably is releasably secured'thereto by cap screws (not shown).

The bottom wall. of the hub 11 is provided with a central openingtherethrough and a bearing 13 mounted within. the bottom wall of the hubrotatably receives the stem 14' of a burner IStherein. As is illustratedin the drawing, the stem 14 of the burner assembly is hollow topermit.the passage therethrough of a fuel which is ignited and burned at theburner plate 16a of the burner head- 16. Preferably, burner head 16 isarcuate and covers a substantial are so that a suflicient heating timeis provided. Since burner assemblies of this general character are wellknown inthe art it is believed unnecessary to'herein describe the burnerin further detail.

The" upper endof the stem 14 Within the hub 11 is enlarged and-isequipped with an upwardly-extending annular 'flange 17' that is coveredby an air shutter 18 that is rigidly secured to a fuel conduit 19 and insealing relation therewith by a collar 20. The flange 17 is intended torotate relative to the cap 18, and any air admitted between the partsmerely mixes with the combustible fuel andmain air supplied through airshutter 18.

The conduit 19 is equipped at its lower end with an orifice 22 throughwhich the fuel must flow in' its passage into the burner assembly 15.The conduit 19 at itsopposite endleads to a source of fuel which may beany one of a number offuels but is preferably gas. A valve 23 interposedin the conduit 19 and is preferably adapted for automatic control of theflow of gas to the burner assembly 15.

A branch conduit 24 extends downwardly from the main supply conduit 19and leads to a pilot burner 25 that communicates with the interior ofthe casing 10 through an aperture in the side wall thereof. A valve 26inserted in the branch conduit 24 permits manual control-o'f the flow offuelto the pilot burner 25 which can be equipped with a conventionalsafety device (not shown); In the installation illustrated the pilotburner is stationary and as the burner assembly 15 rotates within thecasing 10, in a manner to be hereinafter described, the pilot burner iseffective to ignite the fuel present at the burner plate 16. It will beappreciated, however, that other pilot structures may be employed and,for example, a pilot designed to rotate with the burner assembly 15 andto perhaps be carried thereby might well be substituted for tha specificstructure illustrated.

The casing 10 is equipped with a flue 27 that communicate's with' theinterior thereof and extends outwardly and'away from the casing andprovides an escape for the products of combustion resulting from theburning of the fuel at the burner plate 16 and pilot 25.

It is seen that a plurality of cylinders 28 are mounted within theinterior of the casing 10 and may be rigidly secured'within the annularchannel provided between the inwardly-extending projections 11:: andltla'provided respectively bythe hub 11 and casing 10'. The cylindersPreferably are rigidly secured to the casing and hub and are heldstationary within the casing. Any number of cylinders 28 may be providedand in the sectional illustration given, three are shownnarnely, thecylinder 28 shown at the left in section, the cylinder 28a showncentrally by dotted lines, and the cylinder 28b shown in elevation atthe right of the drawings. The construction of each of the cylinders issubstantially identical and in setting out such construction attentionwill be directed specifically to the sectional showing at the left ofthe illustration.

Each cylinder 28 is provided with an enlarged upper portion 29 and alower portion of reduced diameter 30. Mounted for reciprocatory movementwithin each of the cylinders is a piston 31 of relatively-large diameterand that sealingly engages the walls of the enlarged cylinder portion 29and a piston 32 of reduced diameter that reciprocates within and insealing engagement with the walls of the reduced cylinder portion 30. Apiston rod 33 is rigidly secured to the piston 31 and piston 32 so thatthese members move in unison.

The space 34 between the upper surface of the piston 31 and closuremember 12 may be referred to as the compression space, while the space35 between the lower surface of the piston 32 and bottom wall 36 of thecylinder may be referred to as the work space. Upon reciprocation of thepistons, a fluid is intended to be compressed within the space 34 whilethe expansion and contraction of a fluid within the work space 35 isadapted to power the apparatus and bring about the reciprocatorymovement of the pistons.

It will be appreciated that the annular closure member 12 provides a topwall for each of the cylinders and is, therefore, in sealing engagementwith the vertical walls thereof. The closure 12 is provided with aninlet port 37 communicating with the interior of the cylinder 28 and adischarge port 38 similarly communicating with the interior of thecylinder 28. It should be understood that similar inlet and dischargeports are provided for each cylinder in the structure. The inlet port 37is adapted to be closed .by'a recessed valve 39 during the compressionstroke of the piston 31 and the valve is supported in normally openposition upon a retainer 40. The discharge port 38 is equipped with avalve 41 adapted to sealingly engage the valve seat 42 during thesuction or intake stroke of the piston 31. The inlet port 37 is in opencommunication with a suction manifold 43 which may communicate through aconduit 44 with an evaporator 45 which provides a source of expandedfluid and fluid which is to be compressed. The discharge port 38communicates with a discharge manifold 46 which is in open communicationthrough a conduit 47 with a condenser 48 that forms a part of therefrigeration system. To complete the refrigeration system a conduit 49equipped with an expansion valve 50 connects the condenser 48 andevaporator 45. Thus it will be apparent that compressed fluid is fedthrough the discharge manifold 46 and conduit 47 to the condenser 48where, after being cooled, it is expanded through the valve.50 and intothe evaporator 45 from which it is drawn into the compression space 34through the conduit 44 and suction manifold 43.

It will be appreciated that the compressor apparatus so far describedand which will be hereinafter further described may be employed in thecompression of fluids in numerous systems and that the refrigerationsystem herein illustrated is exemplary only.

The lower ends of the cylinder portions 30 must be provided with anexpansible fluid and I prefer to provide and maintain the supply of suchfluid through a conduit 51 which at one end is in open communicationwith the high pressure side of the condenser 48 through the bleed valve52. Branching upwardly from the high pressure supply conduit 51 are aplurality of conduits 53, 53a, 53b, etc., that in turn communicatethrough the check valves 54, 54a and 54b respectively with the cylinderpor- 4 tions 30, 30a and 305. It will be apparent that the branchconduits must enter the casing 10 and extend to the lower cylinderportions at an elevation sufliciently high to prohibit interference withthe free rotation of the burner assembly 15.

It is also desired to prevent excessive accumulation of fluid within thelower cylinder portions, and to prevent such accumulation branchconduits 55, 55a and 5512 are provided that are in open communication atone end with their respective cylinder portions and at their oppositeends communicate with a high pressure bleed valve unit 56 that in turncommunicates with the high pressure side of the condenser 48 through themain return conduit 57. The bleed valve unit 56 is arranged so that thevalves therein permit the flow of fluid from the branch conduits andinto the main return conduit 57 when the pressure of the fluid withinthe lower cylinder portions reaches some predetermined value. In theillustration given, valve unit 56 contains three separate valves 56a,56b, and 56c, respectively controlling the flow through lines 53b, 55a,and 55. These valves are backed by compression springs 58a, 58b, and580. As already indicated, the operation of these valves is to permitbleeding in and out from the actuating cylinders. In other words, valveunit 56 provides means for removing refrigerant in controlled amountsfrom the reduced lower portions 30 of cylinders 28. I

In thecompressor of this invention, it is desired to alternately heatthe lower cylinder portions and then cool the same following the heatingthereof. I prefer to cool the cylinders by spraying a coolantthereagainst through the nozzle 59. While any suitable coolant may beused to bring about the relatively rapid cooling of the heated cylinderportions, I have found that the same coolant, which is preferably water,used to cool the refrigerant within the condenser 48 may beadvantageously employed. Therefore the nozzle 59 is rigidly mountedwithin the end portion of an elbow 60 that is extended at one side andforms a coolant line 61 and which is rigidly secured to a dependingsleeve 62 which at its upper end receives and is rigidly secured to aplug 63 that may be an integral part of the burner assem'bly 15. Thesleeve 62 should sealingly engage the plug 63 to prevent the flow ofcoolant from the upper end of the sleeve. The sleeve 62 is rotatablysupported within a bearing 64 mounted centrally within the bottom wallof the casing It). The sleeve extends downwardly through the bearing andcasing and rotatably receives. therein the coolant supply conduit 65which has interposed between it and the inner surface of the sleeve abearing seal 66. Thus, the burner assembly 15, coolant conduit 61 andsleeve 62 are free to rotate relative to the coolant supply conduit 65.

' Coolant is supplied to the conduit 65 through the supply line 67 whichwinds through the condenser 48 in a conventional manner and extendsoutwardly therefrom and communicates at its lower end with a source ofcoolant which, as hereinbefore indicated, may be relatively cool water.The water pressure control valve 68 is preferably interposed in thecoolant supply line leading to the condenser 48 and is operative toprevent the flow of coolant to the condenser until the system isoperating at sufficient capacity to require the cooling of thecondenser. A bypass 69 equipped with a bypass control valve 70 is placedabout the control valve 68 and permits a limited flow of coolant to thecondenser 48 until the main control valve 68 has opened.

Extending downwardly from the junction of the cooland lines 65 and 67 isa coolant control conduit 71 that at its opposite end is preferablyconnected to a drain for carrying away coolant that flows therethrough.A metering valve 72 is interposed in the-control conduit 71 and 1sequipped with a valve arm 73 extending laterally therefrom. The arm 73has a bifurcated'end portion that is received between the flanges 74 -ofa sliding sleeve 75 mounted for reciprocation upon a shaft 76 and whichhas its position determined by a governor 77. The governor 77 may beconventional in all respects and may include a' collar 78 rigidlyconstrained against longitudinal movement upon the shaft 76 and theconventional fly balls 79, the position-of which is determined-by thespeed of rotation of the shaft 76 and which are rigidly secured to thesleeve 75 and thereby determine its position upon the shaft. v

At its upper end the shaft 76 has rigidly-secured thereto a spur gear80' which meshes with the drive gear 81 rigidly carried by the sleeve62. Rotation of the sleeve 62, then; is operative through the gears 80and 81 to rotate the shaft 76;

The bottom wall of the casing has mounted in an aperture providedthereby a water trap 82' that at its opposite" end communicates with'adrain whereby the coolant sprayed against the cylinders-andwhichcollects upon the bottom wall of the casing is'disposed of. Toprevent excessive spray throughout the interior of the casing 10, ashield 831s carried by the conduit 61 and extends upwardly and about thenozzle59 and is adapted to partially enclose the lower end portions 30'of the cylinders. It will be apparent that the shape of the shield 83must be such that the reduced end portions 30 of the cylinders will notimpede-movement of the shield as-the conduit 60 rotates withinthecasing. 1

The nozzle 59 should be angularly'd-isposed within the end of the elbow60 so that the reaction of the coolant forced through the-nozzle willcause the nozzle and conduit'60, as well as the burner assembly andsleeve 62, to rotate by jet action;

Operation- Eventually in its rotary movement the burner 16 is ignitedand the heat'developed by the burning of the fuel heats the expansiblefluid within the lower portion of the reduced cylinder ends and brings:about a change of state of such fluid.

As the fluid evaporates within the work space 35, the piston 32. isforced upwardly as is the rod 33 and piston 31. The volume of. workspace. 34 is thereby decreased and fluid, which may-be refrigerant,within such compression" space is compressed and is forced outwardlythrough the discharge port 38, into the discharge manifold 46,.

and in compressed condition through the conduit 47 and into thecondenser 48. As the burner assembly rotates from beneath the cylinder,the nozzle 59 is eventually brought into position therebelow and thespray of coolant from the nozzle chills the lower end portion 30 of thecylinder and causes the gas thereinto condense. The

pressure exerted by such fluid upon the piston 32 is thereby decreasedand the piston 32, rod 33" and piston 3'1 move downwardly within thecylinder.

Asthe pistons move downwardlywithin the cylinder, the valve 39 is openedwhile the 'valve 41 is closed and fluid is drawn into the compressionspace 34 through the inlet port 37 and from the s'uctionrmanifold 43,refrigerant suction conduit 44 and evaporator 45. When the burner isagain brought into heat-exchange relation with the cylinder, the fluidwithin the cylinder portion 30 is evaporated and the refrigerant withinthe compression space 34 is condensed, and the cycle is repeated.

Since a plurality of cylinders are provided, compression of somerefrigerant and the forcing of the compressed refrigerant into thecondenser 48 is carried on simultaneously with the suction of expandedrefrigerant from the evaporator 45. Thus the compression of refrigerantis carried on at a relatively even rate. The spray of coolant comingfrom the nozzle 59 cools the cylinder portion it impinges against, whilethe shield 83 tend-s to collect the liquid and to channel it downwardlyto the bottom of the casing 10 whereby the trap 82 carries it to asuitable drain. At the same time, the jet from the nozzlethat cools thecylinders also impart-s rotary movement to the coolant assembly andburner assembly rigidly secured thereto. The combustion gases are takenfrom the interior ofthe casing through the flue 27.

When it is desired to stop the system, the main valve 23 may be closedso. that the pistons can no longer be heated. Selectively the pilot maybe permitted to continue burning or it, too, may be shut otf, as well asthe bypass control valve 70.

The burner 15 may occupy an arc ranging from, for example, to 240", asdesired. Thus a rather pro longed heating of each cylinder is providedduring movement of the burner assembly and if the cylinders aresufiiciently close together at least two cylinders may be heatedsubstantially simultaneously.

The governor mechanism 77 automatically regulates the speed with whichthe burner assembly 15 and coolant unit rotate. For example, if thevalve 68 in the coolant supply line to the condenser 48 is open to aconsiderable extent, a large amount of coolant will flow upwardly andthrough thenozzle 59. Thus the greater flow ofliquid from the nozzlewould tend to speed up rotation of the burner assembly and coolantassembly, while if the valve 68 were not open to a great extent,

less liquid would flow through the nozzle and the speed or rotation ofthe burner and nozzle assembly would tend to decrease. With the valve72and governor assembly 77 controlling the same, the speed of rotationcan be held fairly constant, for if the tendency of the assembly is torotate-at a greater velocity the governor opens the valve 72 to agreater extent and more of the coolant flows to drainthrough the conduit71. Therefore less liquid is present at the nozzle 59 and the speed ofrotation will not be greatly increased. On the other hand, if the rotaryspeed tends to decrease, the governor 77 closes the valve 72 and more ofthe coolant flows to and through the nozzle 59 whereby the rotary speedof the burner assembly, etc., is maintained at the preselected speed.

Fluid and lubrication for the piston 32 is supplied to the cylinderportion 30 through the bleed valve 52, conduit 51 and branch conduit 53;When the pressure within the cylinder portion 30 is low, the bleed valve522 permits some high pressure fluid to flow from the high pressure sideof the condenser 48 tothe piston 30. On the other hand, excessiveaccumulation of the fluid within the cylinder portion 30 is-checked byreturn flow through the branch conduit 55 and bleed valve 56 if thepressure within the lower cylinder portion 30 exceeds by a pre selecteddifferential, for which the bleed valve 56 is set, the pressure of therefrigerant at the return side of the condenser 48. For example, thebleed valve 52 may be designed to bleed a small amount of high pressurerefrigerant from the condenser and into the lower cylinder portions whenthe pressure in the condenser is approximately 150 pounds per squareinch and when the pressure within the evaporator is approximately 40pounds per square inch. At the fully retracted position or lowermostposition of the piston, 32, most of the expansible fl-uid' within thelower cylinder portion 3lliwill have been condensed and the pressuretherein may be about pounds per square inch when heat is supplied to thecylinder and the fluid begins to evaporate. If the valve 52 is set toopen at a pressure of about pounds per square inch, each of the lowercylinder portions 34) will be fed a small amount of refrigerant duringthe time the pressure therein is below the 130 pounds per square inchlevel. Similarly, the bleed valve 56 may be set to open whenever thepressure within the cylinder portions 30 exceeds a value such as 300pounds per square inch, which will be attained during some portion ofthe cycle.

While in the foregoing specification an embodiment of the invention hasbeen set out in considerable detail for purposes of illustration, itwill be apparent to those skilled in the art that considerable deviationmay be made in these details without departing from the spirit andprinciples of the invention.

I claim:

1. In apparatus of the character described, at least one one cylinderhaving an enlarged end portion and a reduced end portion, an enlargedpiston mounted for reciprocatory movement in the enlarged end portion ofsaid cylinder, a piston of reduced diameter mounted for reciprocatorymovement in the reduced end portion of said cylinder, means rigidlyconnecting said pistons together, said cylinder being provided with avalve-equipped inlet port and a valve-equipped outlet port both adjacentthe upper end of said enlarged end portion of the cylinder, means forproviding a heat-expansible fluid in the cylinder portion of reduceddiameter, and means for alternately heating and cooling said cylinder atthe end thereof of reduced diameter.

2. In apparatus of the character described, at least one cylinder havingan enlarged end portion and a reduced end portion, and enlarged pistonand a reduced piston rigidly connected together and mounted respectivelyfor reciprocatory movement in the enlarged end portion and reduced endportion of said cylinder, means for providing a heat-expansible fluid inthe reduced end portion of said cylinder, and means for alternatelyheating and cooling the reduced end portion of said cylinder comprisinga fuel burner for heating and a liquid spray for cooling said reducedend portion.

3. In compressor apparatus, a plurality of spacedapart cylinders eachequipped with a piston mounted therein for reciprocatory movement, meansfor providing an expansible fluid in one end of said cylinders, a burneradapted to move successively into heat-exchange relation with said oneend portion of each cylinder, means for supplying fuel to said burner,and means for successively cooling each of said-cylinders following theheating thereof by said burner.

4. Apparatus according to claim 3 in which each of said cylinders isequipped with an enlarged end portion and a reduced end portion, saidexpansible fluid being provided in said reduced end portion.

5. The structure of claim 4 in which said means for cooling each of saidcylinders comprises a water spray arranged to discharge thereagainst.

6. The structure of claim 5 in which said water spray is providedthrough an angularly oriented nozzle communicating With a source ofWater under pressure.

7. In compressor apparatus, a casing providing a chamber therein, apluralityof cylinders mounted in spaced-apart relation about an arewithin said casing, piston means in each of said cylinders forreciprocatory movement, means for providing an expansible fluid beneatheach piston means, a burner mounted within said casing for rotarymovement with respect to said cylinders in an arcuate path of traveltherebeneath, a coolant supply means adapted to communicate with asource of coolant under pressure and being mounted for rotation withinsaid casing and being rigidly secured to said burner assembly, and anozzle carried by said coolant assembly and being angularly orientedwith respect to the cylinders and adapted to discharge liquid coolantunder pressure thereagainst. v

8. The apparatus of claim 7 wherein a valve-equipped conduit suppliescoolant to said coolant assembly, and governor means arranged with saidcoolant assembly and with said last-mentioned valve controls the openingof said valve and thereby the supply of coolant to said nozzle.

9. The structure of claim 8 in which a pilot is provided for ignitingsaid burner assembly, and in which a safety control valve is arrangedwith said burner assembly for controlling the flow of fuel thereto.

10. In engine-compressor apparatus of the character described, acylinder, a piston mounted for reciprocatory movement within saidcylinder, means for providing a heat expansible fluid within saidcylinder at one end thereof, heating means supported for movement withrespect to said cylinder and being movable into heat exchange relationwith the end thereof having the heat expansible fluid therein, and acoolant device mounted for movement with respect to said cylinder formovement into heat exchange relation with the end thereof having saidheat expansible fluid therein, said heater and coolant device beingarranged for successive movement into the aforesaid relations with saidcylinder.

11. In a compressor structure, a plurality of cylinders each having apiston reciprocable therein, said cylinders being spaced apart and eachbeing adapted to have a heat expansible fluid introduced into one endthereof, a burner and a liquid spray device supported for movementsuccessively into substantial alignment with the aforesaid one end ofeach cylinder, said burner being adapted to heat that end of eachcylinder to expand a fluid contained therein and said liquid spraydevice beingadapted to impinge liquid on that end of each cylinder tocool such fluid contained in the aforesaid one end.

12. The apparatus of claim 11 in which said liquid spray devicecomprises a nozzle for discharging liquid under pressure against saidcylinders, said burner and liquid spray device being connected togetherand said nozzle being angularly oriented With respect to said cylinderswhereupon the impingement of liquid discharged therefrom against thecylinders is effective to move the burner and liquid spray devicesuccessively into alignment with the various cylinders.

13. In compressor apparatus of the character described, at leastonecylinder equipped with a piston mounted therein for reciprocatorymovement, means for providing a heat-expansible fluid in one end of saidcylinder, a burner movable into heat exchange relation with the said oneend of said cylinder, means for supplying fuel to said burner, andcooling means for cooling said one end operatively associated with saidburner, said cooling means successively moving said burner into saidheat exchange relation with said cylinder and itself into coolingrelation with'said cylinder.

References Cited in the file of this patent UNITED STATES PATENTS626,652 Dean June 6, 1899 871,114 Drewett NOV. 19, 1907 1,1 ,641 ComfortJune 29, 1915 7 ,653 Levering Apr. 11, 1916 89,067 Lieberman Nov; 13,1945 66 Lorphelin June 1, 1948 2,637,981 Russell May 12, 1953

